Ebike isnt working

[Tom@WashDC]

Welcome aboard Chris. You might want to start a new thread for this inquiry rather than piggyback the OP thread.
There isn't enough info in your description to diagnose your problem in my opinion. Am I correct that you want faster takeoff, and higher top end?

1. What type of transmission do you have? Single speed? 9spd, 12spd? if a multi-speed rear cassette, what is the teeth count?
2. If single speed what is the rear cog teeth count?
3. What size front chain ring?
Your transmission is going to influence your top end for sure.

3. What is your battery BMS max amps, and nominal amps?
4. What is your controller max and nominal amp rating?
5. What is your motor KV rating? (RPM / V)

Before you purchase anything else, I recomend you go here and do some reading: Motors don't have fixed power ratings

 

[Cdonovin]

Thank you I will follow Your advice it has a 7/speed hub. I’m not looking for crazy speed I just want this wheel to operate in the parameters for a 2000watt. I think I’m more interested in a much stronger take off for 0-20mph. I’d be to scared to go over 30mph I just want to know that it’s there. Your other questions from 2 thru 5 are a bit over my head so I really can’t answer it.. I will start a new thread. Thank you for responding
Chris
Wilmington NC

 

[indianajo]

Direct drive hub motors inherently have low torque at low speeds, picking up as the RPM get into the power band. As you have noticed, good torque at 15 mph and above.
Tom@Wash questions are irrelevant for a direct drive hub motor. Sprockets with a hub motor mean your legs provide the torque the motor will not. Direct drive hub motors are about 12" in diameter and drag without power about like being in 2 sprockets bigger than you really are.
Note torque rating of motors is useless without a specification of what speed the motor is turning when that torque is produced. Most vendors quote a peak torque production at some unnamed speed.
6 to 7" diameter hub motors are geared, the motor runs 5 times faster than the wheel. The start torque is about 5 times higher than DD motors. My Mac12T geared hub motor will start 330 lb without assistance on a 15% grade, then pull up to about 6 mph without help from my feet. The limitation of geared hub motors is that they will burn the winding if lugged up a steep grade for an hour or more. I cross 77 hills in 3.7 hours on my Mac12T, but they are rollers and I carry the speed of a downhill up the next hill. Some of these hills are 12-15% grades. My Mac12t tops out at 23 mph, whereas a previous 10 winding geared hub topped out at ~25 mph.
There are also mid drive motors, that pull through the chain to the rear wheel. These typically have a 4:1 speed reduction internal and will also start on grades. Mid-drives cool themselves better than geared hubs. A common myth is that the sprockets provide torque increase for a mid-drive motor. 99% of ebikes have a biggest rear sprocket of 32 teeth or smaller, so with a 46 tooth front sprocket most mid-drives come with the speed is increased and torque reduced even in the slowest speed. In most cases mid-drives do not support a throttle. Mid-drives do wear out chains 2-5 times faster than a hub motor. Especially 10 speed up chains, which are very thin. By contrast I get ~5000 miles and 2 1/2 years out of the 8 speed chains on my bike with a geared hub motor.
Installing a mid-drive on an existing frame requires special tools and skill. See the diykits forum topic below for details on mid-drive conversion. https://forums.electricbikereview.com/forum/diy/
The highest voltage supported by geared hubs and mid-drives tends to be 48 v. 36 v geared hubs and mid-drives are beginning to dominate the market. While you can buy a geared hub power wheel for your existing frame that will start better and have lower top speed, you are stuck with your 72 v battery. Be sure to dispose of it in a legal manner at a governmental recycling center.

 

[harryS]

Direct drive, DD, motors will start slow, but it's all relative. All my motors are geared, either 5:1 or 12:1. The latter on a 20" folding bike will lift my front wheel if I am sitting back on the seat.. Whoops.

Most of the amazon reviewers don't have a speed issue. The 48V DD motors seem to easily go 30 mph. Maybe your battery doesn't have the size it needs to support the current.

 

[Cdonovin]

 

[Cdonovin]

I’m not sure If this is direct drive or geared but low torque till you hit 9 mph then it starts pulling. Top end 30mph
for 2000 watt it seems like it is not performing to its design

 

[PCeBiker]

I’m not sure If this is direct drive or geared but low torque till you hit 9 mph then it starts pulling. Top end 30mph
for 2000 watt it seems like it is not performing to its design

That motor looks too thin to be a geared hub motor in my opinion.

 

[PCeBiker]

I found this, which looks like what you have, and they list it as a Non-gear Hub Motor.

 

[PCeBiker]

I’m not sure If this is direct drive or geared but low torque till you hit 9 mph then it starts pulling.

Yeah, that's how direct drive motors work.

Top end 30mph
for 2000 watt it seems like it is not performing to its design

Your motor will go over 50mph.

It's got a governor on it to limit the speed to 30mph.

They limit the speed to 20mph in Canada, so just just after the power starts to kick in, it shuts off.

Direct drive motors aren't a good choice for Canada unless you get one with windings geared for torque.

 

[indianajo]

I’m not sure If this is direct drive or geared but low torque till you hit 9 mph then it starts pulling. Top end 30mph
for 2000 watt it seems like it is not performing to its design

Foot rulers are $1 with the school supplies at any dollar store. Is the diameter 12", or 6 to 7"? If 12", it is DD. If 6-7" it is geared.

 

[Cdonovin]

I have a 72 volt battery supposedly a 2000 watt hub. I set and reset the parameters on the SW900 display speed is set to 100
i can’t imagine why it won’t go over 30 mph let alone not get moving till 9 mph

 

[PCeBiker]

I have a 72 volt battery supposedly a 2000 watt hub. I set and reset the parameters on the SW900 display speed is set to 100
i can’t imagine why it won’t go over 30 mph let alone not get moving till 9 mph

I set my speed to 72 kph.
I've tried everything to get my bike to go faster than 32 kph.
Setting the wheel size to the smallest size changed the speedometer reading but my actual speed (using GPS) was still only 32 kph.

The laws in Canada state that an ebike can't go faster than 32 kph and the ebike importers must comply.

It's probably the same in the USA with a 30 mph limit.

You would have to do some kind of firmware update on your controller/display to unlock it.

There's probably a way to unlock your ebike, but finding out how is difficult and illegal.

I can turn my controller up to 1200 Watts but it will still only go 32 kph.

I'll just get to 32 faster than when I have the power turned down.

I can feel the power cut out when I hit 32 kph.

 

[Tom@WashDC]

I have a 72 volt battery supposedly a 2000 watt hub. I set and reset the parameters on the SW900 display speed is set to 100
i can’t imagine why it won’t go over 30 mph let alone not get moving till 9 mph

Glancing at the reviews on Amazon the results seem to vary, probably correlated to the battery voltage and max amp output of the battery.

1. Owner weighs 240lbs, 48V-1500W, with a 52V 20Ah battery. Reports 34mph.
2. Owner waighs 200+lbs (version/battery unk) Reports 45mph.
3. Ower weighs 260lbs, 2,000 Watt version with 72v 80Ah, continuous 35ah battery, reports 74.5 mph. "this kit will cause the bike to pop a big wheelie"

Question: In your display settings is the P14 Controller Current Limit set to match your controller maximum output?
"1-20 Amps, some versions of sw900/controller allow higher values.
Sets the current (amp) limit of your controller"

SW900 LCD Display / S830 LCD Display User Manual

How to set up an eBike LCD Display? SW900 LCD Display Manual. S830 LCD Display Manual.

elecbikeparts.com